raft_consensus-test: fix mock method
raft_consensus-test: fix mock method

One of the mock methods changed number of arguments. This fixes the mocking
and squashes a warning emitted by clang 3.7.

Change-Id: Ia8e4d83b12ab9bb549fccd94a73ec4bae5ed53e8
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/6745
Tested-by: jenkins
Reviewed-by: Michael Percy <e07a1fd797b473a9c849e618aa2ce06d8055760b@cloudera.com>

EvilMcJerkface/kudu,cloudera/kudu,helifu/kudu,helifu/kudu,cloudera/kudu,cloudera/kudu,andrwng/kudu,helifu/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,InspurUSA/kudu,andrwng/kudu,andrwng/kudu,helifu/kudu,InspurUSA/kudu,cloudera/kudu,helifu/kudu,andrwng/kudu,InspurUSA/kudu,cloudera/kudu,InspurUSA/kudu,InspurUSA/kudu,EvilMcJerkface/kudu,cloudera/kudu,EvilMcJerkface/kudu,EvilMcJerkface/kudu,andrwng/kudu,andrwng/kudu,helifu/kudu,helifu/kudu,InspurUSA/kudu,cloudera/kudu,helifu/kudu,EvilMcJerkface/kudu,andrwng/kudu,andrwng/kudu,helifu/kudu,InspurUSA/kudu,andrwng/kudu,cloudera/kudu,cloudera/kudu,InspurUSA/kudu,EvilMcJerkface/kudu